1. Field of the Invention
The present invention is related to private communications networks and more particularly, to integrating wireless communication devices on a public wireless network to a private communications network.
2. Background Description
A private communications network, such as a private voice network, is a full featured local telephone network. A typical private communications network may include, for example, a communications server or private branch exchange (PBX) server linking together wire connected digital phones for a particular enterprise, e.g., phones located in offices on a common campus. The digital phones may be cordless to allow some mobility within a specific local area and sometimes are Internet protocol (IP) based for easy expansion, e.g., simply by connecting extra IP phones. Local users can share both data and voice based information across the private network to improve productivity. Thus, such a private communications network provides user mobility and easy access for telecommuting, as well as low cost from using minimizing external lines.
On a typical such private communications network, some phones may have a direct line with a dial in direct (DID) number and others may be accessible as extensions from a main number or switchboard number. The main number may be answered by a voice menu or receptionist. Each phone has its own unique identification on the network, i.e., its own in network phone number. Point to point calling within the network is normally done by dialing an abbreviated number string, one to five digits long. Dialing an out of network number may be a two step process of first dialing out (e.g., dialing 9) and then dialing the number of the party being called. Dialing into the private communications network may entail dialing the main number to get the private network dial tone or voice menu and then, dialing the called party's extension.
Public wireless communications networks such as cellular or cell phone networks provide a wide mobility range, typically nationwide. Each cell phone has its own unique phone number. To connect to a cell phone, the caller dials a number just like calling someone on a land line connected to the plain old telephone system (POTS). Thus, normally, a caller dials seven to ten digits for a local cell phone number and eleven or more for a long distance number. Likewise the cell phone caller dials seven to ten digits for a local number and eleven or more for a long distance number.
Currently, remote users can connect over a high speed link (e.g., over a high speed broadband connection such as a Digital Subscriber Line (DSL) or a cable modem line) to the communications server using a personal computer (PC) to seamlessly communicate with other connected users. However, for access to all of the communications server features, a broadband connection must be available just to use VoIP in a proprietary client application from a remote PC. Unfortunately, broadband is far from being universally available and seldom available to travelers. When broadband is not available, the only access to the communications server is with a modem over a public switching telephone network (PSTN) and remote users still cannot access all of the private communications network features. At best, a cell phone connection to the private communications network is no different than any other incoming call and has little access to any of the private communications network features.
Thus, there is a need to extend private communications networks beyond the physical range of wire connected devices, especially to distant users connecting through a public wireless connection and especially, to make private communications network features available to wireless users.